JPS6285357A - Memory protecting device - Google Patents

Memory protecting device

Info

Publication number
JPS6285357A
JPS6285357A JP22661685A JP22661685A JPS6285357A JP S6285357 A JPS6285357 A JP S6285357A JP 22661685 A JP22661685 A JP 22661685A JP 22661685 A JP22661685 A JP 22661685A JP S6285357 A JPS6285357 A JP S6285357A
Authority
JP
Grant status
Application
Patent type
Prior art keywords
write
instruction
memory
fixed data
equipment
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP22661685A
Inventor
Hisao Yagi
Original Assignee
Nec Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Abstract

PURPOSE: To protect the specified area of the memory of the microprocessor of a terminal control equipment, from the program of the microprocessor by making write to a memory area possible or impossible, based on a command from a central control unit.
CONSTITUTION: A central control unit 4 sends out successively a fixed data write instruction to the terminal control equipment 2. The equipment 2 reads this instruction through an inputting/outputting circuit 7D by a microprocessor 12, and writes a data in the fixed data area of a memory 14 in accordance with the instruction. When the write of the fixed data of a necessary portion is ended, the unit 4 sends out a write inhibiting instruction to the equipment 2. When the write inhibiting instruction is detected by a control information analyzing circuit 10, a memory write permitting signal line 11 becomes an inhibited state. As a result, by a memory controlling circuit 13, the writing to the fixed data area from the processor 12 becomes impossible, and the fixed data area is protected completely until a write permitting instruction is received again.
COPYRIGHT: (C)1987,JPO&Japio
JP22661685A 1985-10-09 1985-10-09 Memory protecting device Pending JPS6285357A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP22661685A JPS6285357A (en) 1985-10-09 1985-10-09 Memory protecting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP22661685A JPS6285357A (en) 1985-10-09 1985-10-09 Memory protecting device

Publications (1)

Publication Number Publication Date
JPS6285357A true true JPS6285357A (en) 1987-04-18

Family

ID=16847994

Family Applications (1)

Application Number Title Priority Date Filing Date
JP22661685A Pending JPS6285357A (en) 1985-10-09 1985-10-09 Memory protecting device

Country Status (1)

Country Link
JP (1) JPS6285357A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7123564B2 (en) 1998-06-15 2006-10-17 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7269110B2 (en) 1998-06-15 2007-09-11 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7123564B2 (en) 1998-06-15 2006-10-17 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7269110B2 (en) 1998-06-15 2007-09-11 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7283446B2 (en) 1998-06-15 2007-10-16 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7362678B2 (en) 1998-06-15 2008-04-22 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7447133B2 (en) 1998-06-15 2008-11-04 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof
US7697389B2 (en) 1998-06-15 2010-04-13 Samsung Electronics Co Ltd Recording medium for storing write protection information and write protection method thereof
US8139458B2 (en) 1998-06-15 2012-03-20 Samsung Electronics Co., Ltd. Recording medium for storing write protection information and write protection method thereof

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